We are entering a new age in molecular genetics in which we can use sequence data from genome projects to dissect cell, developmental and disease pathways more completely and more sensitively than ever before. We need to develop new experimental approaches to analyze the vast amounts of data that are now available from genome projects. C. elegans is the only animal model system with a complete genome sequence, and thus will play a leading role in establishing approaches that make use of the full genome sequence. One key functional genomics approach is to use DNA microarrays to define changes in gene expression patterns during development and during the onset of disease. Our goal is to set up a center at Stanford for the worm academic community to perform DNA microarray experiments. To my knowledge, our lab is the only one that has C. elegans DNA microarrays, and so we are the only potential resource for DNA microarrays for the academic C. elegans community. We will plan DNA microarray experiments with our collaborators, and then perform DNA microarray experiments using RNA samples that they send to us. We are using DNA microarrays to identify genes that are expressed in specific tissues, regulated by specific transcription factors), by specific cell signaling pathways, by programmed cell death, by expression of homologs of human disease genes in transgenic animal or by addition of various pharmaceutical drugs. The microarray data will be presented and analyzed on our microarray website. I estimate that we can perform approximately 100 microarray experiments each year, collaborating with up to 50 different labs. Each of our collaborators will benefit by identifying gene expression differences between two mutant strains or growth conditions, and may design subsequent experiments to determine the function of expression pattern of target genes predicted by the microarray experiment. The microarray center at Stanford will benefit from each collaboration by being able to establish a global matrix of gene expression patters, so that we can analyze global patterns of gene expression. The next two to three years is a critical time to develop DNA microarray technology, and C. elegans microarrays can play an important part in developing this technology because these miroarrays will be the only one containing the complete genome from a metazoan.